1. Field of the Invention
The present invention relates to information communication systems. More particularly, the present invention relates to a system and method for zero intermediate frequency (ZIF) filtering of information communicated in wireless networks.
2. Background Information
Conventionally, off-the-shelf semiconductor chip sets can be used to communicate information in networks, such as, for example, wireless mesh networks or the like. Such chip sets can include several chips (e.g., three or four or any suitable number), with each chip comprising a stage in the communication process. In such communication systems, as the transmission power is boosted, concomitant noise, distortion and spurious signals also increase. Accordingly, additional filtering can be appropriately added between each or any of the chips in the chip set to provide suitable filtering between each stage of the communication process.
As technology has progressed, however, the multiple chips in these chips sets have been integrated into a single chip or device. Consequently, filtering noise between individual stages of the communication processing becomes problematic once the various stages are integrated into the single chip or device. In particular, for example, for wireless communication systems, the noise, distortion and spurious signals produced by a zero intermediate frequency (ZIF) chip or the like can limit the amount of amplification of the signal by the power amplifier chain at the given (wireless) signal frequency (e.g., 2.4 GHz for I.E.E.E. 802.11 applications or the like). For ZIF transmission systems, simply using filters at the given signal transmission frequency cannot adequately filter such noise, distortion and spurious signals to allow higher power transmissions meeting regulatory certification requirements. Additionally, ZIF receive systems have limited capacity to reject noise in a high-noise environment or to reject high-level interferers, and filtering at the given signal reception frequency does not substantially improve the performance of such systems.
Therefore, there is a need to suppress and filter noise, distortion and other spurious signals in such communication systems, particularly in such systems that use a single chip or device for communication processing.